Emerald Green Arborvitae (Thuja occidentalis 'Smaragd')

Emerald Green Arborvitae

Thuja occidentalis 'Smaragd'

Its dense emerald foliage stays vibrant year-round, a compact evergreen hedge staple. Coniferous shrub; common name: Emerald Green Arborvitae.

Full sun
1–2/week
Beginner
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Plant Needs

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Sunlight Prefers full sun to partial shade; requires at least 6 hours of direct daily sunlight to maintain dense, vibrant foliage and compact growth habit
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Watering Water deeply when the top 5–7 cm of soil dries out; avoid overwatering to prevent root rot, especially in poorly drained soils
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Temperature Extremely cold-hardy, tolerating temperatures down to -30°C; withstands hot summer temperatures with consistent soil moisture, but avoid prolonged drought conditions
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Characteristics

  • Leaf: Scale-like, flattened bright emerald green foliage arranged in overlapping fan-shaped sprays
  • Cones: Tiny oblong brown female seed cones; small yellow male pollen cones release pollen in early spring
  • Stem: Densely branching woody stems forming a tight, upright columnar habit
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Care Guide

Watering

Water deeply once weekly during dry periods to maintain consistent soil moisture

Fertilization

Apply a balanced slow-release granular fertilizer once in early spring to support new growth. Do not fertilize in autumn or winter to avoid stimulating tender new growth that may be damaged by frost

Eggshell powder top-dressing:Crush thoroughly dried eggshells into a fine powder; sprinkle 1–2 tablespoons around the base of the shrub and gently work into the top 2 cm of soil to avoid root disturbance
Pruning
  • Lightly shear new growth in early spring to maintain the narrow columnar shape and dense foliage
  • Remove dead, damaged, or diseased branches at any time to improve airflow and overall plant health
  • Avoid heavy pruning into old, woody stems, as regrowth may be sparse and uneven
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Toxic; contains thujone which may cause neurological and gastrointestinal symptoms

Humans: Ingestion of large amounts may cause mild gastrointestinal upset including nausea and abdominal pain

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Garden Uses & Culture

Culture: Symbolizes longevity and resilience in landscaping; commonly used in formal hedges and privacy screens for its year-round vibrant color

Usage: Ornamental hedge, privacy screen, foundation planting, and container specimen for small gardens